This invention relates to installation guides; and more particularly relates to novel and improved installation guide for coaxial cable end connectors used in splicing the cable to another cable or connecting to a post or terminal.
I have previously devised end connectors for effecting sealed engagement with one end of the coaxial cable by applying a crimping force to a sleeve on the connector body which will uniformly reduce the diameter of the sleeve into a generally conical configuration which snugly engages the end of the cable, reference being made to U.S. Pat. Nos. 5,392,508 and 5,596,800. End connectors of the type disclosed in those patents require the use of a separate crimping tool and are primarily intended for use by professional cable installers. However, it was found that there are a number of situations in which it was not feasible to purchase a crimping tool or where a crimping tool was not available either to splice coaxial cables together or to connect one end of the cable via a connector fitting into a post or terminal. In order to fulfill that need, I devised other versions of crimping devices in which crimping rings were pre-installed on the end connector in such a way that the installer could crimp the end connector onto a cable using standard tools, such as, a crescent wrench or pliers. Subsequently, other low cost crimping tools have been developed to facilitate crimping of the end connector in an efficient and reliable manner.
In utilizing crimping devices in the form of pre-installed crimping rings which extend beyond the end or entrance of the electrically conductive member into the end connector has resulted in substantially increased spacing between the end of the crimping ring and the inner sleeve which receives the electrically conductive pin member. As a result, in attempting to insert the pin member and surrounding dielectric into the sleeve, if not properly centered, makes it difficult to properly insert the outer jacket and braided conductor layer of the cable into the annular space between the inner and outer sleeves of the connector body without damaging or distorting the outer layers but in any event can result in an extremely poor fit between the cable and connector as a preliminary to the crimping operation. Maintaining proper alignment and centering of the pin is therefore important in assuring a good fit and effecting sealed engagement between the end connector and cable and is especially critical in connectors used in digital communications.
Accordingly, it is an object of the present invention to provide for a novel and improved installation guide for securing a cable to another member and in such a way as to maintain precise concentric alignment in a dependable and highly simplified manner.
Another object of the present invention is to provide for a novel and improved installation guide for connecting a coaxial cable to an end connector or for splicing two coaxial cables together which is low cost, requires a minimum number of assembly steps, assures precise alignment and sealed engagement between the parts, and prevents shorting between the electrically conductive foil layer on the cable and the conductor pin on the cable as well as conductor portions of the starter guide.
It is a further object of the present invention to provide for a novel and improved installation guide inserted into an end connector having a pre-installed crimping ring as a preliminary to insertion and crimping of a coaxial cable to the connector and in such a way that the installation guide can either be automatically discarded when the parts have become properly assembled or can remain in place as a part of the assembly.
It is a further object of the present invention to provide for alternate forms of installation guides which either may be temporarily or permanently mounted within an end connector to assure assembly of the coaxial cable in precise alignment with another cable or with a post or terminal to which it is to be attached.
In accordance with the present invention, an installation guide has been devised which is comprised of an elongated insert adapted for insertion into engagement with an inner wall of the end connector and wherein the guide projects forwardly toward the entrance of the connector and is recessed at its forward end to receive the male end or electrically conductive pin portion of the cable to retain the cable in centered relation for insertion into sealed engagement as a preliminary to being joined to the connector, such as, by crimping. In one form, the installation guide is slidable rearwardly with the cable as it is advanced into mating relation to the end connector, and the guide is free to fall away from or be removed from the opposite end of the connector prior to connection of the cable to another cable or to a post or terminal, as the case may be.
In another form of invention, the installation guide is in the form of a tubular insert placed in the inner wall of the end connector and defines a guide passage for advancement of the conductive portion of the cable therethrough and into engagement with another elongated conductor member at the one end of the connector opposite to insertion of the cable. This alternate form is adapted for use more with even greater length connectors than the first form, such as, a BNC connector in which an extension of the conductive portion of the cable is required in order to make the necessary electrical connection with the terminal. Accordingly, the guide insert itself is formed with a pin-receiving bore which is surrounded by seizure prongs which contract against the pin when the pin is inserted in to the bore. The guide tube itself is preinstalled into the inner sleeve to a first position and, when the conductor pin is inserted into the bore, the end of the dielectric surrounding the conductor pin will abut the end of the guide tube and force it rearwardly a limited distance until the pin itself becomes seized by the prongs at the opposite end of the connector to the entrance. Thus, the guide tube serves the dual purpose of an improved electrical connection with minimal return losses and proper alignment of the conductor pin and dielectric within the inner sleeve of the connector.
As a still further modification of the form of invention, the guide insert is in the form of an extension pin with a pin-receiving bore surrounded by seizure prongs to contract against the conductor pin of the cable when the latter is advanced through the crimping ring. However, in place of the tubular insert of the alternate form just described, the extension pin is preassembled into a starter plug which is supported at the front end of the end connector and in turn supports the extension pin in a position to receive the conductor pin on the cable as it is initially advanced through the crimping ring. The starter plug will fall off once the extension pin is advanced through the connector until the starter plug reaches a limit stop. In this way, the assembler can determine that the cable has been advanced the proper distance into the connector for complete assembly.
It is therefore to be understood that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed and reasonable equivalents thereof.